Plug seal for containers



May 11, 1948. J. M. SCHORR 7 2,441,514

PLUG SEAL FOR CONTAINERS Filed April 19, 1946 Y INVENTOR 4m ATTORNEY Patented May 11, 1948 UNITED STATES PATENT OFFICE 2,441,514 PLUG SEAL FOR OGNTAINERS John Michael Schoi'r, New Orleans, La.

Application April 19,1946, semi No. 663,559

1 Claim, 1

This invention relates to plug seals for con-tain-v ers and has for its object to provide a seal for containers having a high vacuum interior. The sealing. action is against the exterior atmospheric pressure.

The inventionconsists in a plug having a, circular flange and a screwthreaded plug portion adapted to engage a screwthreaded bore in the container, the container having a table portion and a shoulder portion towards the exterior of the container and beyond its screwthreaded portion, the table and shoulder portions supporting and being engaged by a rubber or similar material washer, huggingly engaging the plug portion, with a brass or similar material washer placed on the outer surface of the rubber washer having a cir cular opening closely contacting with a cylindrical machined part of the plug, the plug having a flange extending over the upper surface of the brass washer, the opposed surfaces being milled or machined to reduce friction to the greatest extent possible, and. thus permitting a ireed'omof movement,- yet providing a sealing. action the pressure of the flange exerting a pressure on the brass; washer andupcn the rubber'wash'er. The surfaces. of the metalparts being highly milled or machined to providea close fitting; is essentiah The invention will be more fully described hereinafter, an embodiment shown inthe: drawings, and the invention will be finally pointed out in the claim.

In. the accompanying drawings,

F 1 is a central. section of the: improved seal applied to: a container;

Fig. 2is a top view ofv the-upperplug';

Fig- 3 is a side View with parts in section, in exploded positions; and V Fig. 4' is'a bottom view of the lower" plug.-

Similar characters of reference indicate corresponding parts throughoutthe various-views.

Referring to the drawingsand more particw larly to Fig. 3, the improved seal for containers subjected to-high partialvacuum, consistsof four parts, an upper plug In; a brass washer I I", a rubber washer l2,land a lower-plug [3;

The container I5 isprovided with a conical 2 at right angles to the table portion It extends from the table portion W to theexterior wallor the container. The internal diameter of the shoulder portion is larger than the diameter of the bore l6 to the extent of the length of the table portion [8.

The lower plug [3" is Slightly conical in shape and has exterior screw threads as at 20, these screwthr'ead'sbeing of a kind to mesh with the screwthieads- W or the bore f6 of the container wall. The conical bore l6 and the conical plug I 3, taper inwardly in the direction from the outside to the inside or the container wall. This per mit the entrance oi the pics from the outside of the container; A projection 2| of square shape serves for the application of a wrench Orbther tool; The lower plug [3 has an interior cylindrical bore 22' open at its top, which is intericrly bore: l6 having its orifice at the interior the s'crewthread'ed as at 23. It also has circumferentially spaced screwthrea-ded sockets 2'4, preferably two'in number diametrically disposed for the reception of Allenscrews. The exterior screwthreads 20 extend about two thirds up along the lowerplug', and the remaining circumferential portion 25- is very closely milled or machined to provide a very smooth surface, which 'i's an import-ant feature;

The rubber wash-er l Z has an internal diameter; which is abt iut one sixteenth of an inch l'e's's than the external diameteror the milled portion 25 of the lower plug ML The external diameter or the w'asher F2 is suhstant'ially' equal to the internal diameter of the shoulder IF of the container wall The thickness of the rubber washer i2 is about one half or'atli-ttlemorethan one half of the height of the milled portion- 25.

The: brass washer ll-' has a thickness, preferably somewhat less than the thickness of the rubber Washer; The combined thicknesses of the rubber and" brass washers: I 2 and it, is about equal to the height of the" milled portion 25.

The-brass; washer H has its upper surface; and particularly its axialwal-l: Ha very closely milled or machined, which is an important feature. The lower surface of the brass washer H is-p-ref erablyknurled to engage the upper surface of the rubber washer l2.- Where a: certain kind of surface on the rubber washer is used. the engagement betweenthe brass and rubber washers is such that linu'rli'ng is not necessary The internal diameter of the wall" I'la'is substantially tion 26 exteriorly threaded as at 21, so shaped as to mesh with the interior threads 23 of the lower plug l3. The length of the screwthreaded plug portion 26 is less than the depth of the bore of the lower plug. Above the exterior screwthreaded portion 26, a circular flange 28 of an external diameter substantially equal to the external diameter of the brass washer H, extends outwardly of the threaded portion 26. The lower surface 29 of this flange 28 is very closely milled to provide a very smooth surface, which is an important feature. circumferential groove 30 at about one half of the extending length of the flange 28. The outer diameters of the flange 28 and of the brass washer II are each slightly less than the internal diameter of the shoulder portion I9 of the container wall. An exterior projection 3! of square shape serves for the application of a wrench or other tool. Screwthreaded sockets 33, with countersunk portions, extend through the flange 29 for the passage of the Allen screws 34 which engage the sockets 24 of the lower plug l 3.

To assemble the unit, the brass ring or washer H is placed over the milled portion 25 of the lower plug 3. The very close milling provides a snug lit. The upper plug H1 is screwed into the screwthreaded bore 22 of the lower plug 1 3, as far as it will go, and the Allen screws 34 lock the plugs together. The rubber washer or gasket I2 is then slipped over the threaded part of the lower plug, and pushed up to and under the brass washer or ring I l, with the inner diameter of the rubber washer l2 hugging the milled part 25, the rubber Washer being slightly bulged. The upper and lower plugs so combined are ready for use in the steel or other similar container, which has been specially milled to receive the plug. The screwing home of the lower plug portion I3 into the bore 56 of the container presses the'rubber, and flattens the bulge and expandsit radially against the shoulder 99 of the container as shown in Fig. 1, which shows the external diameter of the rubber larger than the external diameter of the brass ring, though these external diameters were the same, as shown in Figure 3. In so rotating the combined plugs, the smooth surface of the flange 2B rides on the smooth upper surface of brass washer l l, and the oil in the groove 3!! facilitates this sliding action, to the end that the brass washer H is not rotated, but pressed axially against the rubber washer, the highly machined surfaces of the part 25 and internal bore Ha of the brass washer permitting a free movement axially of the brass washer l I.

The inside diameter of the rubber washer is about one sixteenth of an inch smaller than the milled portion 25 or hub of the lower plug l3, which thereby makes a very close contact and a seal. When the threads 20 of the plug l3, are screwed into the container threads l1, that is, when the combined plug is screwed in, the rubber washer makes a very close contact and seal with the table portion N3 of the container and forms a seal. The pressure on the rubber washer increases, the bulge passes on to the shoulder portion l9 of the container and makes a very close contact and seal, the one thirty-second inch provision insuring such a seal. Finally the brass washer pressing on the rubber, makes a very close contact and seal,. while at the same time pressure forces applied to the rubber washer force the rubber against thetable l8 and shoul- The lower surface 29 has a der l9. Thereby, a four point pressure and sealing efiect is achieved.

The purpose of the brass surface 29 of the upper plug l0 and brass surface of the brass ring or washer I I is to provide slippage, when the surface 2=9 slidingly rotates on the brass ring H, which may be held by contact with the rubber ring 12. Thereby a uniform pressure on the rubber is provided without dragging the rubber, even though some unevenness or irregularity may be in the table portion l8 of the container. The groove 30 for oil improves the slippage between the milled brass surfaces, the oil film serving while under pressure also as a seal.

It is important that the inside axial wall Ila of the brass ring H fits very snugly with only the slightest clearance or tolerance on the hub or milled portion 25 to keep the rubber from oozing out where it would tear, drag the rubber along and break the seal.

While not intended as a limitation, the following dimensions will aid in the making of the improved container seal. The plug portion 26 is with a l S. A. E. thread, the flange 29 is 2%"; the length of the flange The brass ring is 2 external diameter, with .a 1%" opening, a width of and a thickness of /8". The rubber ring has an external diameter of 2 an opening diameter of 1%"; the length of the flange 2", thickness T g. The lower plug has the bore with a 1" S. A. E. thread, the hub or milled portion of a diameter of 1%", and an axial length of with the axial length of the threaded portion of and external threads of 1 standard pipe thread. ,The nut portion extends about 1%". The external 1 pipe thread is tapered, that is, the largest diameter is at the upper part of the bore !6. The tap of the wall of the container or steel barrel is tapered to conform. The Allen screws are A.".

The combined plugwith its sealing action'is specially intended for use where a very high degree of vacuum in the container is essential.

.I have described several forms of my invention, but obviously various changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claim:

I claim:

In a sealing plug for containers requiring a high vacuum contents, in which the container has a screwthreaded bore, a table portion and a shoulder portion at right angles to the table of a diameter larger than that of the bore, the combination of a plug having an interior screwthreaded bore, and an exterior screwthreaded portion with a machined cylindrical portion without screwthreads, a second plug exteriorly screwthreaded for engaging said interior bore, said second plug having a circular flange with a milledlower surface extending laterally of the cylindrical portion, a metallic washer having an outer diameter substantially that of the outer diameter-of said flange, and having a central opening of a'diameter equal to the outer diameter of the cylindrical portion of the first plug, allowing for tolerance, and having its upper surface and wall of the opening milled, and a Washer of resilient material seated on said table portion, and having'a central opening of a di- 'ameter less than the outer diameter of the cylindrical portion of the first plug, the outer diameters of the metallic washer and rubber washer being substantially those of the shoulder portion in the container, the first and second plugs be- 5 ing connected by screws for the rotation of both plugs simultaneously, the close fit of the metallic washer and the cylindrical portion providing a seal to the rubber washer and the rubber washer providing a four point seal on the screwing of the combined plug into the bore of the container.

J OHM MICHAEL SCHORR.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 457,415 68,016

6 UNITED STATES PATENTS Name Date Ecaubert Dec. 7, 1909 Riegel Feb. 17, 1925 Woods Feb. 25, 1930 Thompson Apr. 18, 1939 FOREIGN PATENTS Country Date Germany Mar. 15, 1923 Austria Feb. 25, 1915 Great Britain Aug. 2, 1928 

